- Mensajes: 21
- Gracias recibidas: 3
Toggle Switches
9 años 2 meses antes - 9 años 2 meses antes #245
por Ray
Respuesta de Ray sobre el tema Toggle Switches
Hi, the change in revisions only affects the drawing on the back of the PCB, F and G (which is the current right now) have exactly the same layout and gerber files.
SW2 (on the left) is the mix switch,
- when is in up position, it allows the guitar input signal to go to ground, and never reaches the last summing op-amp.
- when is in down position, nothing stops the guitar input signal to go to the last op-amp in summing configuration.
To be sure that DAC0 and DAC1 are working properly you can load the sinewave generator.
Please be extra carefully checking DAC outputs, it is very easy to blow them. There are two test points on the shield to measure DAC0 and DAC1 after a capacitor, so there is no risk of high DC currents. Measure the DACs on pins 2 and 3 of the second TL072 is also a good point.
Let us know about your progress.
SW2 (on the left) is the mix switch,
- when is in up position, it allows the guitar input signal to go to ground, and never reaches the last summing op-amp.
- when is in down position, nothing stops the guitar input signal to go to the last op-amp in summing configuration.
To be sure that DAC0 and DAC1 are working properly you can load the sinewave generator.
Please be extra carefully checking DAC outputs, it is very easy to blow them. There are two test points on the shield to measure DAC0 and DAC1 after a capacitor, so there is no risk of high DC currents. Measure the DACs on pins 2 and 3 of the second TL072 is also a good point.
Let us know about your progress.
Por favor, Identificarse para unirse a la conversación.
9 años 2 meses antes - 9 años 2 meses antes #254
por Vince
Respuesta de Vince sobre el tema Toggle Switches
I remove those two TL072 : no problem of pin... and put it back in the board and, fantastic, now it works...
I believe there were a contact problem with one TL072.
As my scope was ready i took few pictures of signals.
The distorsion is interresting to see with a very small square signal when the sound is good. The loss of level is impressive before a good distorsion.
Input signal :
DACO and DAC1 signal - inverted
Metronome output signal
I believe there were a contact problem with one TL072.
As my scope was ready i took few pictures of signals.
The distorsion is interresting to see with a very small square signal when the sound is good. The loss of level is impressive before a good distorsion.
Input signal :
DACO and DAC1 signal - inverted
Metronome output signal
Por favor, Identificarse para unirse a la conversación.
Tiempo de carga de la página: 0.102 segundos